In unconsolidated formations created for the extraction of oil and gas, horizontal and deviated wells may be provided with integrated sand screens and inflow control device (ICD) completions, such as those described in GB2448069. Such wells are usually drilled using a drilling mud containing solids for bridging purposes and to prevent fluid loss into the formation. Once the well has been drilled, the drilling mud is replaced with a non-damaging fluid, called Drill In Fluid (DIF), which is cleaner than the conventional drilling mud. However, the DIF still contains some solids to form mud cake to prevent fluid loss.
Prior to completing the reservoir section of the wellbore with the ICD screen completions, the DIF is either replaced by or conditioned to a low or zero solids system. If, however, the DIF in the wellbore is not replaced by or conditioned to a low or zero solids system, and the ICD screen completions are lowered into an unconditioned section of mud which contains solids, the ICD screen completions may plug and, as a result, well performance and productivity may be poor or significantly decline. Even if the ICD screen completions are introduced into a conditioned well, screen plugging can occur as a result of mud cake and invaded mud solids flow back.
It is therefore an aim of the present invention to provide a flow control apparatus and method of cleaning the flow control apparatus, which addresses at least some of the afore-mentioned problems.